Common Irrigation Pump Problems and Their Causes

While standard municipal water pressure works fine for garden hoses, irrigation systems require much higher pressure to operate effectively. Agricultural irrigation typically uses propeller, submersible, deep-well turbine, and centrifugal pumps.

Irrigation pumps are essential in almost all agricultural operations, moving water from lower to higher levels or raising water pressure for field distribution. Pumps are the nucleus of modern irrigation systems - when selecting an irrigation pump, you must consider water source availability, required flow rate, total suction head, and total dynamic head.

Common Causes of Irrigation Pump Problems

Cavitation

Cavitation occurs when bubbles form in fluid as local pressure drops below the fluid’s vapour pressure at a given temperature. These bubbles cause pitting within the pump’s impeller, casing, and volutes, weakening the metal and significantly increasing resistance to flow.

The result is decreased pumping efficiency. Cavitation also reduces pump service life by introducing shock loads to the motor and shaft.

Wear and Tear

Groundwater contains various particulate matter that can negatively impact pump operation. Regardless of concentration or size, these particles roughen the pump’s interior surface through scouring. Over time, this reduces system efficiency until the pump eventually fails to produce sufficient lift for crop water supply.

Fouling

Fouling most commonly occurs in distribution lines connecting to a pump’s intake or outflow. Pumps themselves can also experience fouling when extremely fine particulate matter sticks to internal surfaces, or when coarse particles are ingested but cannot be expelled.

Fouling significantly reduces pump efficiency and can eventually cause complete pump failure.

Motor Issues

Common motor-related problems include:

• Insulation damage from motor overheating

• Insulation damage when water enters the motor housing

• Direct contact between the pump rotor and stator surface, causing catastrophic pump or motor failure

Water Level Problems

An irrigation system draws water continuously, as long as groundwater level remains above the pump’s intake point. However, local water level typically drops once the pump starts operating. This drawdown effect can sometimes cause the pump to suck in air when water level falls below the intake point, leading to system problems.

Expert Solutions for Your Irrigation System

If you’re experiencing any issues with your irrigation pumping system, contact our experts at Australian Pivot Solutions - we specialise in delivering cost-efficient solutions to irrigation equipment problems.